Auto merge of rust-lang#93351 - anp:fuchsia-remove-dir-all, r=tmandry

Bump libc and fix remove_dir_all on Fuchsia after CVE fix

With the previous `is_dir` impl, we would attempt to unlink
a directory in the None branch, but Fuchsia supports returning
ENOTEMPTY from unlinkat() without the AT_REMOVEDIR flag because
we don't currently differentiate unlinking files and directories
by default.

On the Fuchsia side I've opened https://fxbug.dev/92273 to discuss
whether this is the correct behavior, but it doesn't seem like
addressing the error code is necessary to make our tests happy.

Depends on rust-lang/libc#2654 since we
apparently haven't needed to reference DT_UNKNOWN before this.

Author: bors

std/Cargo.toml

@@ -15,7 +15,7 @@ cfg-if = { version = "0.1.8", features = ['rustc-dep-of-std'] }
 panic_unwind = { path = "../panic_unwind", optional = true }
 panic_abort = { path = "../panic_abort" }
 core = { path = "../core" }
-libc = { version = "0.2.108", default-features = false, features = ['rustc-dep-of-std'] }
+libc = { version = "0.2.116", default-features = false, features = ['rustc-dep-of-std'] }
 compiler_builtins = { version = "0.1.66" }
 profiler_builtins = { path = "../profiler_builtins", optional = true }
 unwind = { path = "../unwind" }

std/src/sys/unix/fs.rs

@@ -1653,7 +1653,6 @@ mod remove_dir_impl {
         target_os = "illumos",
         target_os = "haiku",
         target_os = "vxworks",
-        target_os = "fuchsia"
     ))]
     fn is_dir(_ent: &DirEntry) -> Option<bool> {
         None
@@ -1664,7 +1663,6 @@ mod remove_dir_impl {
         target_os = "illumos",
         target_os = "haiku",
         target_os = "vxworks",
-        target_os = "fuchsia"
     )))]
     fn is_dir(ent: &DirEntry) -> Option<bool> {
         match ent.entry.d_type {